Man is trying to make active use of the different sources of renewable energy at all times: The solar energy, for example, is used in water heating, cooking, and in greenhouses to help to grow food, and of course to extract electrical energy using photovoltaic cells.
The second example of renewable energy is the wind energy. It is used to generate mechanical power or electricity using the wind turbines. The wind turbines convert the kinetic energy in the wind into mechanical power which in turn can be used to generate electricity to power homes, businesses, school, etc.
The third example of renewable energy is the hydropower energy, where the kinetic energy in the water such as dams, waterfalls and rivers can be used to generate electricity. Other examples of renewable energy resources are the biomass and bio-fuel energy, and the geothermal energy.
Nowadays, researchers are trying to combine different energy resources to maximize the benefits of these resources. For example, the solar tower which was first suggested by Isidoro Cabanyes from Spain in 1903, combines the chimney effect, the greenhouse effect and the wind turbine to maximize the use of the solar energy. It is designed to use the solar energy to generate a wind tunnel where a wind turbine can be placed to generate electricity.
It is well known that water is about 800 times denser than air, even a slow flowing stream of water can yield considerable amounts of energy. Therefore, it is very important to maximize the use of water energy whenever it is possible. The suggested design is meant to maximize the use of the water energy by creating an artificial flow stream by lifting the water above the ground level and reuse its kinetic energy to generate electricity.
The major problem facing this idea is how to lift the water or how to pump it up at a very low or at no cost. People are using the standard hydraulic pumps to lift the water but then the energy generated by the falling water will be used by this pump and make it of no use.